<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>输出某年某月的天数</title>
</head>
<body>
    <script>
        function a(y,m,d){
            alert(y+"年"+m+"月"+d+"日");
        }
        function sa(y,m){
            if(m=2){
            if((y%4==0 && y%100!=0) || (y%400==0)){
                a(y,m,29);
                }else{
                a(y,m,28);
                }
            }else if(m == 4 || m == 6 || m == 9 || m == 11){
		        a(y,m,30);
            }else{
		        a(y,m,31);
	}
        }
        sa(2024,11);
    </script>
</body>
</html>